suppose i need a 2s lipo with 15 amp discharge current
so which should i use :headscratch:
2s 20c 750ma
or
2s 15c 1000ma
both combinations can meet your requirement
You can choose anyone as both of them are compatible with ur requirements. However, the 2s 15c 1000mah will give you a greater flight time than the 2s 20c 750mah.
It is better to use a battery whose discharge capacity is at least 20% more than the maximum load current for safety sake.
Yes I missed that part but exactly as Rao uncle has said, choose a battery with about 15-20% greater discharge capacity than what is required.